On a non-stick cookie sheet, place the dried chiles and bake them at 400 degrees for 3 to 4 minutes or until just fragrant. Remove them from the oven and set aside to cool. When the chiles are cool to the touch, remove and discard their stems, seeds, and inner membranes.

Meanwhile, in a medium saucepan, place the water and bring it to a boil. Add the dried chiles, remove the saucepan from the heat, and set aside for 1 hour to allow the chiles to rehydrate and soften.

In a small non-stick skillet, sauté the onion in the olive oil for 5 minutes or until lightly browned. Add the garlic, oregano, and cumin, and sauté an additional 2 minutes. Remove the skillet from the heat and set aside.

After the chiles have soaked for 1 hour, transfer the chiles and a little of the soaking liquid to a food processor, and pureé until smooth. Add the sautéed onion mixture, remaining soaking liquid and the other remaining ingredients, and process until smooth.

Return the sauce to the medium saucepan and simmer for 10 minutes to allow the flavors to blend.

Transfer the sauce to an airtight container and store in the refrigerator for up to one week, or the sauce can be frozen for later use.

Use as a sauce for enchiladas or other Mexican or Southwestern style dishes, to add flavor to steamed vegetables and grains, or as a condiment.